Off-period belching due to a reversible disturbance of oesophageal motility in Parkinson's disease and its treatment with apomorphine.

Two L-dopa-treated patients with Parkinson's disease who developed distressing belching during "off" periods are reported. In each case, contrast cine radiography revealed disturbed oesophageal motility which disappeared after injection of the dopamine receptor agonist apomorphine. It is suggested that central dopaminergic abnormalities may be important in the aetiology of "off period belching."